Transcriptome analysis identifies genes and co-expression networks underlying heat tolerance in pigs

Area of Science:

• Animal Science
• Genetics
• Reproductive Biology

Background:

• Heat stress negatively impacts pig growth and reproduction, affecting feed intake, weight gain, and farrowing rates.
• Heat tolerance is crucial for pigs to mitigate adverse physiological effects of heat stress.
• Genetic factors and signaling pathways in heat-tolerant pigs remain incompletely understood.

Purpose of the Study:

• To investigate gene expression differences and co-expression networks in pigs exhibiting varying heat tolerance.
• To identify genetic variations and biological mechanisms underlying heat tolerance in pigs.
• To explore potential biomarkers for heat stress response and reproductive performance in pigs.

Main Methods:

• Whole transcriptomic RNA-sequencing (RNA-seq) was employed to analyze mRNA from pig blood samples.
• Boars were classified as heat-tolerant or heat-susceptible based on semen parameter variations under thermoneutral and heat stress conditions.
• Weighted gene co-expression network analysis (WGCNA) was used to identify gene modules associated with semen quality.

Main Results:

• A total of 66 differentially expressed genes were found in heat-tolerant pigs when comparing heat stress to thermoneutral periods.
• 1041 differentially expressed genes were identified when comparing heat-tolerant to heat-susceptible pigs under heat stress.
• Gene co-expression networks revealed modules significantly associated with semen quality parameters in both heat-tolerant and heat-susceptible pigs.

Conclusions:

• Semen quality sensitivity to heat stress can effectively differentiate pig heat tolerance.
• Gene expression profiles provide insights into the biological mechanisms of heat stress response in pigs.
• Identified genes and pathways can serve as potential biomarkers for enhancing pig reproductive efficiency under heat stress.